Pollutant interceptor

ABSTRACT

An apparatus for interception solid matter from fluid flowing through a drain or pipe including a drain or pipe coupling to receive and direct fluid flow netting to intercept solid matter while permitting fluid to pass through, and a netting release that interacts with the netting and the coupling to automatically release the netting when a predetermined amount of solid matter has been intercepted.

FIELD OF THE INVENTION

The present invention relates to apparatus for intercepting solid matterfrom a fluid flowing through a drain, pipe or the like. For example, theapparatus can be used for intercepting waterborne solids in wastewasters, such as storm water run-off, industrial waste waters etc. Theinvention will be primarily described with reference to these latterapplications, although it should be appreciated that the invention isnot so limited, and can find application wherever the interception ofsolid matter from flowing fluids is required.

BACKGROUND ART

A major problem in the release and directing of waters into the naturalwater course is the inclusion of solid matter, which ultimately ends upin the sea and rivers and acts as a pollutant to marine life, beachesand to humans.

Further, the dealing with storm water run-offs and the inclusion ofwater-borne solid pollutants is emerging as one of the greaterenvironmental challenges in the current era.

It is extremely difficult to prevent solid matter from ultimatelyfinding its way to waste waters, storm water run-off etc, and thereforeit would be desirable if solid matter could be removed prior to suchwaters returning to the natural water course.

Pollutant interceptors are relatively new in the art. Existing pollutantinterceptors are known to be subject to fouling and failure. The presentinvention has been developed in this context.

SUMMARY OF THE INVENTION

The present invention provides apparatus for intercepting solid matterfrom a fluid flowing through a drain, pipe or the like, the apparatusincluding:

coupling means adapted for association with an outlet of the drain, pipeor the like and for receiving and directing fluid flowing thereout;

netting means adapted for intercepting the solid matter in the directedfluid and arranged with the coupling means such that the directed fluidcan pass through the netting means; and

netting release means that is adapted for interacting between thenetting means and the coupling means to enable release of the nettingmeans from the coupling means when a predetermined amount of solidmatter has been intercepted.

Apparatus according to the invention can be employed to easily andeconomically filter out water-born solids from fluids such as industrialwaste waters, storm water, etc. Should the apparatus be filled or becomefouled etc., activation of the netting release means allows theapparatus to continue to release fluid from the apparatus, ie. so thatblockages, back pressure etc. are not introduced, and which may haveeven more severe environmental impact. Also, the netting means can bereadily detached, serviced and/or replaced periodically.

In a particularly preferred mode of operation, typically the nettingmeans is periodically serviced, emptied, cleaned etc. so that thenetting release means may not even need to come into operation duringactual use of the apparatus.

When the terminology “drain, pipe or the like” is employed in thisspecification, it includes any type of drainage, whether open orenclosed, conduits, tubes, fluid flow pathways etc.

Preferably, and as a result of restricted fluid flow caused byintercepted solids, the netting release means is activated for releaseof the netting means from the coupling means when, in the apparatus:

(i) a predetermined, level of fluid is reached;

(ii) a predetermined pressure of fluid is reached;

(iii) a predetermined mass of solid matter is reached; or

(iv) the flow of fluid via the netting means is reduced to apredetermined level.

Thus, the apparatus can be configured such that one or more of thesefactors can be used to activate the netting release means.

Preferably the netting release means is activated by a trip mechanismassociated with the coupling means which: in (i) is activated by therise of a float; in (ii) and (iii) is activated by a mechanical,electronic or electrical sensor; and in (iv) is activated at a level offluid flow as recorded by a flow meter. Thus, a variety of “triggering”type arrangements can be employed to sense when a parameter has reacheda predetermined level.

Preferably the netting release means includes a retaining cable meansthat can extend around an outer periphery of the coupling means andreleasably clamp an end of the netting means to the coupling means,wherein the cable means is released when the trip mechanism isactivated. Thus, a simple means for attaching the netting means to thecoupling means can be provided. In this regard, when the terminology“cable means” is employed, any cable, clip, clamp, chain, rope,cord-like or tape-like device (or combinations thereof) is envisaged(such as stainless steel cable, synthetic or natural fibrous ropes,stainless steel chain, plastic woven tapes, hose-type clamp mechanisms,C-shaped leaf spring clips, or combinations thereof etc).

Preferably the cable means is looped around and attached to theperiphery of an opening to the netting means and is adapted, when thenetting means is released from the coupling means, to act as adrawstring to close the opening (eg. whilst the netting means remains ina stream of fluid flowing through the apparatus).

Preferably the netting means is a net bag and is additionally attachedto the coupling means by a safety cord or chain. Preferably the safetycord is attached to the coupling means at one end, and is attached tothe cable means at the other. Preferably the attachment of the safetycord to the cable means is via a ring through which the cable meansextends (ie. so that the ring can be moved along the cable means). Thusin use, the pulling of the cable means on the safety card can cause theopening of the netting means to be closed (in eg. the drawstring-likemanner).

Preferably in (i), the float is retained within a riser pipe and, at apredetermined level of fluid, rises to a height in the riser pipewherein a mechanical release device is activated, which in turn releasesthe netting means from the coupling means.

Typically the mechanical release device includes a pivot arm mounted atone end to the coupling means for pivoting thereabouts and being adaptedat the opposite end for engagement by a catch mechanism that is part ofand is released in the mechanical release device, and wherein the cablemeans is released from the coupling means when the pivot arm is allowed(ie. released) to move away from the catch mechanism.

Preferably the cable means is an endless loop and is looped around thepivot arm.

In alternative configurations, the electronic or electrical sensor, or acontroller associated with the flow meter can interact with themechanical release device to release the pivot arm from the catch.

Typically, the coupling means receives essentially all fluid leaving thedrain, pipe or the line. Preferably the coupling means is a squatcylinder adapted for direct attachment to and/or fitting over the outletend of a correspondingly shaped pipe, tube or drain. The coupling meanscan be attached to the pipe etc. by welding, bolting screwing, riveting,adhesive, etc. However, any other suitable type of mechanism forattaching or positioning the coupling means to or near an outlet offluid flow can be employed.

The coupling means can also be provided with a diversion outlet throughwhich fluid can be directed once a predetermined amount of solid matterhas been intercepted by the netting means. Thus, as a fail-safemechanism where the netting release means for some reason is notactivated, fluid can still be released from the apparatus via thediversion outlet.

In one form the diversion outlet can be a diversion pipe that isselectively closed to fluid flow by an associated valving mechanism (eg.a butterfly or plate is valve), wherein the valving mechanism is openedonce the predetermined amount of solid matter has been intercepted bythe netting means, to then release fluid via the diversion pipe.Alternatively, in a simpler variation, the diversion outlet can beprovided in the form of a diversion weir or outlet passages formed inthe coupling means and which are adapted for allowing an overflow offluid to be released from the apparatus once a predetermined fluid levelhas been reached in the apparatus due to a blockage at or a filling ofthe netting means.

Apparatus in accordance with the present invention can, accordingly,prevent a drain etc., when provided with an interceptor apparatus, frombecoming blocked (eg when there is an inordinate or excessive amount ofsolid matter in the fluid stream, such as in a torrential downpour ofrain). Also, the preferred arrangement of the safety cord enables theintercepted solid matter to be retained, and the drawstring action ofthe bag traps the solid matter for subsequent disposal, rather than itsimply being re-entrained within the flowing fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of thepresent invention, preferred forms of the invention will now bedescribed, by way of example only, with reference to the accompanyingdrawings in which:

FIG. 1 shows a perspective view of a first variation of a solidsinterceptor in accordance with the present invention;

FIG. 2 shows a perspective view of a second variation of a preferredsolids interceptor in accordance with the present invention;

FIG. 3 shows a perspective detail of a preferred release mechanism thatcan be employed with the apparatus of FIGS. 1 and 2;

FIG. 4 shows a perspective detail of a preferred type of float activatedmechanical release mechanism for use with the device of FIG. 2;

FIG. 5 shows the release mechanism of FIG. 4 in a released orientation;

FIG. 6 shows a side elevation of the release mechanism of FIG. 4;

FIG. 7 shows a sectional side elevation of the release mechanism of FIG.4 (being a view in the same orientation to FIG. 6);

FIG. 8 shows a plan elevation of the release mechanism of FIG. 4;

FIG. 9 shows a similar view to FIG. 8 but with the release mechanism ina released orientation;

FIG. 10 shows a perspective view of some of the components of therelease mechanism of FIG. 4;

FIG. 11 shows a perspective view of part of a diversion system for usein apparatus in accordance with the present invention;

FIG. 12 shows a schematic sectional plan elevation through the apparatusof FIG. 11; and

FIG. 13 shows a perspective view of part of a further alternativediversion system for use in apparatus in accordance with the presentinvention.

MODES FOR CARRYING OUT THE INVENTION

Referring to FIGS. 1 and 2, apparatus for intercepting solid matter froma fluid is shown in the form of a water-borne solids interceptor 10. Theinterceptor includes a coupling means in the form of pipe section 12which can be fitted over, attached to or positioned near the end of apipe, tube, drain outlet or the like. Pipe section 12, of course, can beany suitable shape depending on the shape and nature of the outlet fromwhich fluid is being released. The pipe section can be formed from anycorrosion resistant material, such as galvanised welded steel, stainlesssteel, injection moulded plastic etc.

The interceptor 10 shown in FIG. 1 (a similar arrangement would beemployed for the interceptor of FIG. 2) further includes a netting meansin the form of a net bag 14. The bag has an open end 15 that isreleasably attached to the pipe section 12. The bag is typically formedfrom a corrosion resistant material, such as a stainless steel wire,wire mesh or from any rot resistant natural or synthetic fibre material(eg. polypropylene, polyester etc). The open end 15 of the net bag issecured around the external periphery of the pipe section 12 by acontinuous loop of cable 16 (described in greater detail below) andwhich is looped through the end of the bag to be retained to the same.Again, the cable is typically formed from suitable corrosion resistantmaterials, including stainless steel or steel alloy cables (typicallyplastic coated), or from synthetic rope etc.

The cable 16 extends fully around the pipe section circumference, and isof a length such that it can be tensioned (described below) to clamp theopen end of the net between the cable and the pipe section 12, and canbe detensioned to release the same.

As better seen in FIG. 3, the cable 16 includes a section of chain links17 which is attached at each end to loops 18 of the cable viareleaseable shackles 19. In FIG. 2 the loop ends 18 of the cable 16extend between a pair of upstanding pins 20 formed on the pipe section12 (shown also in FIGS. 11 and 13) The pins 20 provide a simple cableguiding arrangement.

Alternatively, as shown in FIG. 1, the cable 16 can extend between apair of pulleys 22 (FIG. 1) mounted on the external surface of the pipesection. The pulley arrangement enables each end of the cable to beguided smoothly during tensioning and detensioning of the cable.

The chain link section 17 is looped around a pivot arm 26 which enablessubsequent tightening of the cable (described below). The pivot arm isattached to the pipe section at bearing plate 27.

The secure fastening of the net bag 14 to pipe section 12 can be furtherfacilitated by providing outwardly flared lips 28, 29 (see FIG. 2)around part of the pipe section, and against which the cable 16 can betensioned to enhance secure fastening of the net bag, and to prevent thecable from being easily displaced (slipped) off the pipe section in use.

FIGS. 1 and 2 in addition show a vertical riser pipe assembly 30, whichis mounted on the pipe section 12, and is in fluid communication withthe interior thereof. The riser assembly is part of a mechanism torelease arm 26 at a predetermined time/occurrence in operation of theinterceptor. Release of arm 26 releases net bag 14 (described below).

The riser pipe assembly includes vertical float chamber 31, in which afloat 32 moves upwardly and downwardly. A hinge bracket and closure tab33 (FIG. 4) for a chamber lid (not shown) is also provided. A viewwindow 34 can be provided in one side of the float chamber (FIG. 1) toenable a user to check that the float has not become fouled (eg. cloggedor entangled) during use.

The lower end of the float chamber communicates with the pipe sectionvia an inlet, and the upper end of the float chamber is provided with acatch assembly 38, which is activated by the float as it moves towardsthe top of the float chamber.

Referring now to FIGS. 4 to 10, it will be seen that the catch assembly38 includes a catch 40 that is pivotally mounted in a bracket 41, whichin turn is bolted to the interior of float chamber 31. The catch isadapted to engage an arm 42 which is part of pivot arm engaging assembly43 (see FIG. 10).

As can be seen in FIG. 4, the arm 42 extends into the interior ofchamber 31, and also extends externally thereof through chamber slot 44(FIG. 5). Attached to arm 42 is a curved support plate 45 which abutsthe external face of float chamber 31 in use (FIG. 4) to set the armextension distance. A finger support 46 extends from curved plate 45 toarm 42, and ensures that the arm is supported and remains reasonablyrigid in use.

The opposite end of arm 42 is pivotally mounted (eg. via a bolt 47) to acatch plate 48, which functions as a catch for pivot arm 26. The catchplate 48 is generally S-shaped, and has an integral pin 49 that extendsdownwardly therefrom in use. The pin 49 is received in a bush 50attached to the external surface of chamber 31 and is supported forrotation in the bush in use.

Referring to FIGS. 8 and 9, FIG. 8 shows the catch assembly in an“engaged” position wherein the pivot arm 26 is captured by catch plate48 (and thereby tensions cable 16 described below). In addition, arm 42is captured within catch 40 to prevent its movement.

FIG. 9 shows the catch assembly in a released configuration whereincatch 40 has been caused to release arm 42 (eg. by the engagementthereagainst of float 32). Thus, because pivot arm 26 is urged outwardlyby the force in cable 16 (ie. due to tension therein to retain the netbag on pipe section 12 in use), the catch assembly is forced to pivotoutwardly. Firstly catch plate is caused by arm 26 to pivot about pin 49(ie. pin 49 rotates in bush 50) and thence arm 42 is caused to pivotabout the support plate 45 at bolt 47). Eventually the catch assembly ispivoted sufficiently out so that the pivot arm 26 is completely releasedtherefrom add falls downwardly. This releases cable 16 from arm 26.

Thus, because cable 16 is looped around arm 26 and is selected to be ofa specific length, when the arm 26 is captured (in the “engaged”position), the cable is tightened, and therefore the net bag open end 15is clamped by the cable to the pipe section 12. However, once the pivotarm is released for pivoting, then the cable is loosened and can move(slide) off arm 26 so that net bag open end 15 is no longer clamped. Theflowing fluid passing through the interceptor then causes the net bag tobecome detached from the pipe section 12.

Typically a retention (or safety) cord 51 is attached to the cable 16 atthe open end of the net bag. In the arrangement of FIG. 1, one end ofthe cord is attached to a fixture 52 arranged externally on the pipesection 12.

In the arrangement of FIGS. 2 and 3, the retention cord 51 includes twosuch sections of cord which extend from lug 54. These two sections areillustrated schematically in dotted outline in FIG. 2. Each end of thiscord is attached to a ring 56 (see FIG. 3), and through which the cable16 (or link section 17) extends. The ring on the upper section ofretention cord 51 is, as shown in FIG. 3, attached to link section 17,whereas the ring for the lower cord 51 is attached to cable 16.

The use of a pair of rings enables the end of the net bag to be gatheredand hung (ie. by suspending the bag from cord 51). In addition, cord 51is typically attached to the lug 54 by a releaseable mechanism (eg. ashackle arrangement).

As described above with reference to FIG. 2, the outwardly flared lips28 and 29 extend only part way around the circumference of the open endof pipe section 12 (ie. the loops are discontinuous at the top andbottom of that open end). This discontinuity of the lips enables thering 56 and chain link 17 located at the upper end of the pipe section,and the ring 56 located at the lower end of the pipe section to passeasily off the pipe section when the net bag is released in use. It willalso be seen that the pins 20 are sloped outwardly (FIG. 2) so that thechain section 17 and ring 56 do not become snagged thereon.

In either arrangement, once the neg bag has been released, the retentioncord prevents it from being washed away. Also, to detach the bag fromthe interceptor before emptying, replacement etc., a user simply needsto detach the retention cord at fixture 52/lug 54, and the user can thenlift the bag via the retention cord.

Also, when the net bag is released from pipe section 12, the cord 51acts on cable 16 to cause it to function as a drawstring and close theopen end of the net bag under the pressure of the fluid flowing throughthe interceptor. Thus, solids intercepted within the net bag are safelyretained within the bag once it has been released from pipe section 12.As described above, the net bag can then be detached, and the solidsemptied, prior to the net bag being re-attached to the pipe section forre-use. Optionally, and if necessary, the net bag can be washed, cleanedand/or repaired.

In use, with the net bag attached to the pipe section as describedabove, and the catch assembly in the engaged configuration, as stormwater passes out of a drain, pipe or the like and into pipe section 12,it is directed into the net bag (FIG. 1) and any debris, solid matter,etc. which is larger than the pores of the net bag is trapped therein.Progressively, over time the net bag fills up. If it occurs that the netbag is not timely emptied or serviced, then the neg bag capacity may becompletely filled, substantially or entirely restricting the flow offluid out of the net bag. This then causes an increase in bag pressure,and, for example, during a storm, water then progressively fills up pipesection 12. Once the pipe section has been filled, the water level thenrises further into vertical rise pipe assembly 30, acting on float 32and causing it to rise within the float chamber 31. Eventually the floatengages against the underside of catch 40 (ie. at arm 58 FIG. 7).

The float continues to rise and lifts catch 40 upwardly causing it topivot at bracket 41. Shoulder 60 of the catch then moves out of abutmentwith arm 42, and arm 42 is then urged to move away from the catchthrough gap 62. The pivot arm engaging assembly is therefore freed, andthe force against pivot arm 26 (ie. from the tension in cable 16 andchain link 17) causes the pivot arm to be pivoted outwardly aboutbearing plate 27. Thus, the entire engaging assembly 43 is caused topivot outwardly (ie. as shown in FIG. 9).

Eventually, the pivot arm 26 moves sufficiently downwards (ie.ultimately laying down against the pipe section 12 and between pins 20)so that the chain link 17 is freed from the pivot arm (ie. slidesthereoff), and thus the cable 16 is loosened. This loosening enables thecable 16 and the bag end to be freed from and pass over the flared lips28, 29 and thus the bag is freed from the pipe section 12.

Further movement of the bag tensions the retention cord 51, and viarings 56, causes it to pull against cable 16. Thus, the drawstring bagclosure of cable 16 is induced. With the end of net bag closed solidsare captured therein and are prevented from dispersing (and re-enteringinto the storm water, waste water, etc.). As described above, the netbag can later be detached from lug 54 and emptied and replaced, orreplaced with a fresh bag, etc.

The movement of the pivot arm 26, and therefore the release of the catchassembly, can be automated. For example, the catch assembly can bereleased when a pressure or fluid sensor detects a predeterminedpressure or fluid level within the solids interceptor (ie. as a resultof the net bag having been filled by solids the fluid level and pressurewould build up in section 12 and this could easily be sensed).Alternatively, when the flow drops to a predetermined level, then a flowmeter positioned either within the interceptor or externally thereof(ie. downstream of the interceptor) can activate the catch assembly torelease the pivot arm.

In a further alternative, an electronic weight sensor that senses theweight of solid matter in the net bag when that bag is filled up withsolid matter can be employed to activate the catch assembly for releaseof the pivot arm. Thus many types of release mechanisms are possible.

Referring now to FIGS. 11 and 12 (where like reference numerals will beused to denote similar or like parts), a diversion outlet is shown inthe form of an offtake pipe 70. In the arrangement of FIG. 11, thevertical riser pipe assembly 30 has been removed. The offtake pipeprovides a backup mechanism should the vertical riser pipe assembly failto release the net. The offtake pipe 70 is open to flow of fluid throughthe pipe section 12, save for the arrangement of a plate valve 72therein. The plate valve is typically closed (shown as an unbroken linein FIG. 12), but can be opened to enable a fluid flow thereabouts(indicated by dotted arrows O) by pivoting the plate valve around apivot axis 74 (supported by appropriate bearings in the offtake pipe).

In use, fluids (eg. storm water, waste water etc.) flows normallythrough the pipe section 12 (in the direction of arrow N) and pass intothe net bag to intercept solid matter. However, once the flow of fluidhas been stopped (eg. due to the net bag's filling up) or has beenreduced to some predetermined level, or the back pressure has built upetc., then plate valve 72 can be opened (eg. moved to the position shownin dotted outline). Thus, fluid is then allowed to bypass the blockage(at the normal opening of the pipe section), and damage to theinterceptor apparatus and back pressure problems, etc. are prevented.

The opening and closing of the plate valve can be mechanically,electro-mechanically, or even manually controlled. For example, theplate valve can be opened by a mechanical arrangement not dissimilar tothe vertical riser pipe assembly but in which case the moving pivot arm26 (or the like) would open the valve, rather than release the net.

Referring to FIG. 13, where like reference numerals will be used todenote similar or like parts, a further alternative diversion outletwill now be described. In the arrangement of FIG. 13, a diversion outletin the form of overflow vents 80, 82 is provided. In this case, thevents arc permanently open and rising fluid level in pipe section 12simply spills out of vents 80, 82 when it reaches the height of thosevents. A similar pair of vents can be provided on the opposite side ofthe plate section (as shown). The vents can be provided in conjunctionwith the offtake pipe arrangement 70 of FIGS. 11 and 12 (if necessary)or can co-operate with internal weirs which enable a spillover of fluidat certain levels. The vents can also be used in conjunction with thevertical riser pipe assembly 30, although in this case the pipe assemblywould need to extend downwardly and into the pipe section to a levelbelow the lowest vent, and the mechanism that activates the catch mayneed to be engaged at a level that is below that of the lower most vent.Again, the overflow vents provide a backup mechanism should the verticalriser pipe assembly fail (or become clogged or fouled etc.).

Preferred construction materials for the interceptor components includestainless steel, galvanised steel (being cheap and readily available)for the pipe section and catch assembly, injection moulded plastics,again being cheap and readily available, ultra-violet light stabilisedpolyethylene, polypropylene, etc for the detachable net bag, stainlesssteel wire ropes and cables for the cable 18, cord 51, stainless steelor plastic for the pulleys 22 etc.

Whilst the invention has been described with reference to a number ofpreferred embodiments, it should be appreciated that the invention canbe embodied in many other forms.

What is claimed is:
 1. Apparatus for intercepting solid matter from afluid flowing through a drain or pipe, the apparatus including: couplingmeans for association with an outlet of the drain or pipe to receive anddirect fluid flowing thereout; netting means for intercepting the solidmatter in the directed fluid and arranged with the coupling means suchthat fluid leaving the outlet can pass through the netting means; and anetting release means for interacting between the netting means and thecoupling means, the netting release means being configured toautomatically release the netting means from the coupling meansresponsive to a predetermined amount of solid matter being intercepted.2. Apparatus as claimed in claim 1 wherein, as a result of restrictedfluid flow caused by intercepted solid matter, the netting release meansis operable to automatically release the netting means from the couplingmeans responsive to one or more of the following: (i) a predeterminedlevel of fluid being reached; (ii) a predetermined pressure of fluidbeing reached; (iii) a predetermined mass of solid matter being reached;or (iv) the flow of fluid being reduced to a predetermined level. 3.Apparatus as claimed in claim 2 wherein the netting release means isactivated by a trip mechanism associated with the coupling means,responsive to one or more of the following: (i) activation by the riseof a float; (ii) activation by a mechanical, electronic or electricalsensor; and (iii) activation responsive to a level of fluid flow beingrecorded by a flow meter.
 4. Apparatus as claimed in claim 3 wherein thenetting release means includes a retaining cable means that extendsaround an outer periphery of the coupling means and releasably clamps anend of the netting means thereagainst; whereby in use, de-tensioning ofthe cable means enables the release of the netting means from thecoupling means.
 5. Apparatus as claimed in claim 4 including a floatthat is retained within a riser pipe such that, at a predetermined levelof fluid, the float rises to a height in the riser pipe whereby itactivates a mechanical release device, and this in turn acts on thecable means to de-tension the same, thereby enabling release of thenetting means from the coupling means.
 6. Apparatus as claimed in claim5 wherein the mechanical release device includes a pivot arm mounted atone end to the coupling means for pivoting thereabouts and being adaptedat the opposite end for engagement by a catch mechanism that is part ofand is released in the mechanical release device, so that the cablemeans is released from the coupling means when the pivot arm is allowedto move away from the catch mechanism.
 7. Apparatus as claimed in claim6 wherein the cable means is provided in the form of an endless loop andis looped around the pivot arm in use when the pivot arm is engaged bythe catch mechanism.
 8. Apparatus as claimed in claim 7 wherein thecable means is looped around and attached to the periphery of an openingto the netting means and is adapted, when the netting means is releasedfrom the coupling means, to act as a drawstring to close an opening ofthe netting means.
 9. Apparatus as claimed in claim 8 wherein thenetting means is a net bag and is additionally attached to the couplingmeans by a safety cord or chain.
 10. Apparatus as claimed in claim 1wherein the safety cord or chain is attached to the cable means and,when the netting release means is released from the coupling means,pulls on the cable means to cause it to close the opening to the nettingmeans.
 11. Apparatus as claimed in any one of the preceding claimswherein the coupling means also includes a diversion outlet throughwhich fluid flowing through the apparatus is diverted in use. 12.Apparatus as claimed in claim 11 wherein the diversion outlet is adiversion pipe that is selectively closed to fluid flow by an associatedvalving mechanism, wherein the valving mechanism can be opened once thepredetermined amount of solid matter has been intercepted by the nettingmeans, to then release fluid via the diversion pipe.
 13. Apparatus asclaimed in claim 11 wherein the diversion outlet is a vent formed in thecoupling means and which is adapted for allowing an overflow of fluid tobe released from the apparatus once a predetermined fluid level has beenreached in the coupling means.
 14. Apparatus for intercepting solidmatter from a fluid flowing through a drain or pipe, the apparatusincluding: coupling means for association with an outlet of the drain orpipe to receive and direct fluid flowing thereout; netting means forintercepting the solid matter in the directed fluid and arranged withthe coupling means such that fluid leaving the outlet can pass throughthe netting means; and a netting release means for interacting betweenthe netting means and the coupling means, the netting release meansbeing configured to automatically release the netting means from thecoupling means responsive to a predetermined amount of solid of solidmatter being intercepted, wherein, as a result of restricted fluid flowcaused by intercepted solid matter, the netting release means isoperable to automatically release the netting means from the couplingmeans responsive to one or more of the following: (i) a predeterminedlevel of fluid being reached; (ii) a predetermined pressure of fluid isbeing reached; (iii) a predetermined mass of solid matter being reached;or (iv) the flow of fluid being reduced to a predetermined level, andwherein the netting release means is activated by a trip mechanismassociated with the coupling means, responsive to one or more of thefollowing: (i) activation by the rise of a float; (ii) activation by amechanical, electronic or electrical sensor; and (iii) activationresponsive to a level of fluid flow being record by a flow meter. 15.Apparatus for intercepting solid matter from a fluid flowing through adrain or pipe, the apparatus including: coupling means for associationwith an outlet of the drain or pipe to receive and direct fluid flowingthereout; netting means for intercepting the solid matter in thedirected fluids and arranged with the coupling means such that fluidleaving the outlet can pass through the netting means; and a nettingrelease means for interacting between the netting means and the couplingmeans, the netting release means being configured to automaticallyrelease the netting means from the coupling means responsive to apredetermined amount of solid matter being intercepted, wherein, as aresult of restricted fluid flow caused by intercepted solid matter, thenetting release means is operable to automatically release the nettingmeans from the coupling means responsive to one or more of thefollowing: (i) a predetermined level of fluid being reached; (ii) apredetermined pressure of fluid is being reached; (iii) a predeterminedmass of solid matter being reached; or (iv) the flow of fluid beingreduced to a predetermined level, wherein the netting release means isactivated by a trip mechanism associated with the coupling means,responsive to one or more of the following: (i) activation by the riseof a float; (ii) activation by a mechanical, electronic or electricalsensor; and (iii) activation responsive to a level of fluid flow beingrecorded by a flow meter, and wherein the netting release means includesa retaining cable means that extends around an outer periphery of thecoupling means and releasably clamps an end of the netting meansthereagainst, whereby in use, de-tensioning of the cable means enablesthe release of the netting means from the coupling means.
 16. Apparatusas claimed in claim 15 including a float that is retained within a riserpipe such that, at a predetermined level of fluid, the float rises to aheight in the riser pipe whereby it activates a mechanical releasedevice, and this in turn acts on the cable means to de-tension the same,thereby enabling release of the netting means from the coupling means.17. Apparatus as claimed in claim 16 wherein the mechanical releasedevice includes a pivot arm mounted at one end to the coupling means forpivoting thereabouts and being adapted at the opposite end forengagement by a catch mechanism that is part of and is released in themechanical release device, so that the cable means is released from thecoupling means when the pivot arm is allowed to move away from the catchmechanism.
 18. Apparatus as claimed in claim 17 wherein the cable meansis provided in the form of an endless loop and is looped around thepivot arm in use when the pivot arm is engaged by the catch mechanism.19. Apparatus as claimed in claim 18 wherein the cable means is loopedaround and attached to the periphery of an opening to the netting meansand is adapted, when the netting means is released from the couplingmeans, to act as a drawstring to close an opening of the netting means.20. Apparatus for intercepting solid matter from a fluid flowing througha drain or pipe, the apparatus including: coupling means for associationwith an outlet of the drain or pipe to receive and direct fluid flowingthereout, the coupling means including a vent formed in the couplingmeans through which fluid flowing through the apparatus is diverted inuse, the vent being adapted for allowing an overflow of fluid to bereleased once a predetermined fluid has been reached in the couplingmeans; netting means for intercepting the solid matter in the directedfluids and arranged with the coupling means such that fluid leaving theoutlet can pass through the netting means; and a netting release meansfor interacting between the netting means and the coupling means, thenetting release means being configured to automatically release thenetting means from the coupling means responsive to a predeterminedamount of solid matter being intercepted.